Method and network node for transmitting ip address information, and method and user equipment for receiving ip address information

ABSTRACT

Provided is a method for making it impossible to track a vehicle performing vehicle-to-everything (V2X) communication through a network. The network may allocate the same IP address to all UEs performing V2X communication. Since the UEs performing V2X communication transmit data using the same IP address, an application server cannot track a vehicle transmitting corresponding data.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application Ser.No. 62/316,594, filed on Apr. 1, 2016, the contents of which are allhereby incorporated by reference herein in their entirety.

TECHNICAL FIELD

The present invention relates to a wireless communication system and,more particularly, to a method and apparatus for transmitting/receivingIP address information.

BACKGROUND ART

Wireless communication systems are widely deployed to provide variouskinds of communication content such as voice and data services.Generally, these communication systems are multiple access systemscapable of supporting communication with multiple users by sharingavailable system resources (e.g., bandwidth and transmission power).Examples of multiple access systems include a code division multipleaccess (CDMA) system, a frequency division multiple access (FDMA)system, a time division multiple access (TDMA) system, an orthogonalfrequency division multiple access (OFDMA) system, a single carrierfrequency-division multiple access (SC-FDMA) system, and a multi-carrierfrequency division multiple access (MC-FDMA) system.

With appearance and spread of machine-to-machine (M2M) communication anda variety of devices such as smartphones and tablet PCs and technologydemanding a large amount of data transmission, data throughput needed ina cellular network has rapidly increased. To satisfy such rapidlyincreasing data throughput, carrier aggregation technology, cognitiveradio technology, etc. for efficiently employing more frequency bandsand multiple input multiple output (MIMO) technology, multi-base station(BS) cooperation technology, etc. for raising data capacity transmittedon limited frequency resources have been developed.

In addition, a communication environment has evolved into increasingdensity of nodes accessible by a user at the periphery of the nodes. Anode refers to a fixed point capable of transmitting/receiving a radiosignal to/from the UE through one or more antennas. A communicationsystem including high-density nodes may provide a better communicationservice to the UE through cooperation between the nodes.

TECHNICAL PROBLEM

A method for effectively processing vehicle application data in avehicle-to-everything (V2X) communication system is needed.

In addition, a method for protecting privacy in a V2X communicationprocess is needed.

The technical objects that can be achieved through the present inventionare not limited to what has been particularly described hereinabove andother technical objects not described herein will be more clearlyunderstood by persons skilled in the art from the following detaileddescription.

SUMMARY

A method for making it impossible to track a vehicle performingvehicle-to-everything (V2X) communication through a network is provided.The network may allocate the same IP address to all UEs performing V2Xcommunication. Since the UEs performing V2X communication transmit datausing the same IP address, an application server cannot track a vehiclethat has transmitted the data.

According to an aspect of the present invention, a method oftransmitting Internet protocol (IP) address information by a networknode in a wireless communication system is provided. The method includesreceiving an IP address allocation request from a user equipment (UE),allocating a specific IP address defined for vehicle-to-everything (V2X)communication to the UE when the IP address allocation request is forV2X communication, and notifying the UE of the specific IP address. Thesame IP address as the specific IP address may be allocated to every UErequesting IP address allocation for V2X communication.

According to another aspect of the present invention, a network node fortransmitting Internet protocol (IP) address information in a wirelesscommunication system is provided. The network node includes a radiofrequency (RF) unit and a processor configured to control the RF unit.The processor may control the RF unit to receive an IP addressallocation request from a user equipment (UE), allocate a specific IPaddress defined for vehicle-to-everything (V2X) communication to the UEwhen the IP address allocation request is for V2X communication, andnotify the UE of the specific IP address. The same IP address as thespecific IP address may be allocated to every UE requesting IP addressallocation for V2X communication.

According to another aspect of the present invention, a method ofreceiving Internet protocol (IP) address information by a user equipmentin a wireless communication system is provided. The method includestransmitting an IP address allocation request to a network node andreceiving IP address information about an IP address allocated to the UEfrom the network node. If the IP address allocation request is forvehicle-to-everything (V2X) communication, a specific IP address definedfor V2X communication may be allocated to the UE. The specific IPaddress may be the same as that allocated to every UE requesting IPaddress allocation for V2X communication.

According to another aspect of the present invention, a user equipment(UE) for receiving Internet protocol (IP) address information in awireless communication system is provided. The UE includes a radiofrequency (RF) unit and a processor configured to control the RF unit.The processor may control the RF unit to transmit an IP addressallocation request to a network node. and receive IP address informationabout an IP address allocated to the UE from the network node. If the IPaddress allocation request is for vehicle-to-everything (V2X)communication, a specific IP address defined for V2X communication maybe allocated to the UE. The specific IP address may be the same as thatallocated to every UE requesting IP address allocation for V2Xcommunication.

In each aspect of the present invention, the IP address allocationrequest may be transmitted by the UE or received by the network using apacket data network (PDN) connectivity request message.

In each aspect of the present invention, the specific IP address may beidentically allocated to UEs requesting connectivity to a PDN for V2Xcommunication or transmitting an IP address allocation requestassociated with an access point name (APN) for V2X communication.

In each aspect of the present invention, the UE may transmit uplink V2Xdata to the network node using the specific IP address.

In each aspect of the present invention, the network node may transmitthe uplink V2X data to an application server for V2X communication.

In each aspect of the present invention, the network node may be apacket data network gateway.

The above technical solutions are merely some parts of the embodimentsof the present invention and various embodiments into which thetechnical features of the present invention are incorporated can bederived and understood by persons skilled in the art from the followingdetailed description of the present invention.

According to the present invention, vehicle application data can beeffectively processed in a V2X communication system.

According to the present invention, V2X communication can be performedwhile satisfying privacy requirements.

It will be appreciated by persons skilled in the art that that theeffects that can be achieved through the present invention are notlimited to what has been particularly described hereinabove and otheradvantages of the present invention will be more clearly understood fromthe following detailed description.

BRIEF DESCRIPTION OF THE DRAWING

The accompanying drawings, which are included to provide a furtherunderstanding of the invention, illustrate embodiments of the inventionand together with the description serve to explain the principle of theinvention.

FIG. 1 is a schematic diagram showing the structure of an evolved packetsystem (EPS) including an evolved packet core (EPC).

FIG. 2 is a diagram exemplarily illustrating architectures of a generalE-UTRAN and EPC.

FIG. 3 is a diagram exemplarily illustrating the structure of a radiointerface protocol in a control plane.

FIG. 4 is a diagram exemplarily illustrating the structure of an radiointerface protocol in a user plane.

FIG. 5 is a diagram illustrating LTE (Long Term Evolution) protocolstacks for a user plane and a control plane.

FIG. 6 is a flow diagram illustrating a random access procedure.

FIG. 7 is a diagram illustrating a connection procedure in a radioresource control (RRC) layer.

FIG. 8 is a diagram illustrating a vehicle-to-everything (V2X)communication environment.

FIG. 9 illustrates V2X message transmission/reception for a V2V/V2Pservice via an LTE-Uu.

FIG. 10 illustrates a V2X message transmission/reception procedure for aV2V/V2P service via an LTE-Uu.

FIG. 11 illustrates a node according to an embodiment of the presentinvention.

DETAILED DESCRIPTION

Although the terms used in the present invention are selected fromgenerally known and used terms while considering functions of thepresent invention, they may vary according to intention or customs ofthose skilled in the art or emergence of new technology. Some of theterms mentioned in the description of the'present invention may havebeen selected by the applicant at his or her discretion, and in suchcases the detailed meanings thereof will be described in relevant partsof the description herein. Thus, the terms used in this specificationshould be interpreted based on the substantial meanings of the terms andthe whole content of this specification rather than their simple namesor meanings.

The embodiments of the present invention described hereinbelow arecombinations of elements and features of the present invention. Theelements or features may be considered selective unless mentionedotherwise. Each element or feature may be practiced without beingcombined with other elements or features. Further, an embodiment of thepresent invention may be constructed by combining parts of the elementsand/or features. Operation orders described in embodiments of thepresent invention may be rearranged. Some constructions or features ofany one embodiment may be included in another embodiment and may bereplaced with corresponding constructions or features of anotherembodiment.

In the description of the attached drawings, a detailed description ofknown procedures or steps of the present invention will be avoided lestit should obscure the subject matter of the present invention. Inaddition, procedures or steps that could be understood to those skilledin the art will not be described either.

Throughout the specification, when a certain portion “includes” or“comprises” a certain component, this indicates that other componentsare not excluded and may be further included unless otherwise noted. Theterms “unit” , “-or/er” and “module” described in the specificationindicate a unit for processing at least one function or operation, whichmay be implemented by hardware, software or a combination thereof. Inaddition, the terms “a” (or “an”), “one”, “the”, etc. may include asingular representation and a plural representation in the context ofthe present invention (more particularly, in the context of thefollowing claims) unless indicated otherwise in the specification orunless context clearly indicates otherwise.

The embodiments of the present invention can be supported by standardspecifications disclosed for at least one of wireless access systemsincluding an institute of electrical and electronics engineers (IEEE)802.xx, a 3rd generation partnership project (3GPP) system, a 3GPP LongTerm Evolution (3GPP LTE) system, and a 3GPP2 system. That is, steps orparts that are not described to clarify the technical features of thepresent invention may be explained with reference to the above standardspecifications.

In addition, all terms set forth herein may be explained by the abovestandard specifications. For example, the present disclosure may beincorporated by reference by one or more of standard specifications,such as 3GPP TS 36.300, 3GPP TS 36.321, 3GPP TS 36.322, 3GPP TS 36.323,3GPP TS 36.331, 3GPP TS 23.303, 3GPP TS 23.401, 3GPP TS 24.301, 3GPP TR22.885, 3GPP TR 23.785, 3GPP TS 23.285, 3GPP TS 23.246, 3GPP TS 23.468,ETS1 TS 302 637-2, ETS1 TS 302 637-3, ETS TR 102 638, and IEEE 1609.12.

Reference will now be made in detail to the embodiments of the presentdisclosure with reference to the accompanying drawings. The detaileddescription, which will be given below with reference to theaccompanying drawings, is intended to explain exemplary embodiments ofthe present disclosure, rather than to show the only embodiments thatcan be implemented according to the invention.

Specific terms used for the embodiments of the present invention areprovided to aid in understanding of the present invention. Thesespecific terms may be replaced with other terms within the scope andspirit of the present invention.

The terms used in this specification are defined as follows.

IMS (IP Multimedia Subsystem or IP Multimedia Core Network Subsystem):

-   An architectural framework for providing standardization for    delivery of voice or other multimedia services over Internet    protocol (IP).

UMTS (Universal Mobile Telecommunications System): Global System forMobile Communication (GSM)-based 3rd generation mobile communicationtechnology developed by 3GPP.

EPS (Evolved Packet System): A network system configured by an EPC(Evolved Packet Core), which is an Internet Protocol (IP)-based packetswitched (PS) core network and an access network such as LTE, UTRAN,etc. The EPS is evolved from UMT.

NodeB: A base station of GERAN/UTRAN which is installed outdoors and hascoverage of a macro cell scale.

eNodeB/eNB: A base station of E-UTRAN which is installed outdoors andhas coverage of a macro cell scale.

UE (User Equipment): A user equipment. The UE may be referred to as aterminal, ME (Mobile Equipment), MS (Mobile Station), or the like. TheUE may be a portable device such as a notebook computer, cellular phone,PDA (Personal Digital Assistant), smartphone, and multimedia device, ormay be a nonportable device such as a PC (Personal Computer) andvehicle-mounted device. The term UE or terminal in the description ofMTC may refer to an MTC devic.

HNB (Home NodeB): A base station of a UMTS network. The HNB is installedindoors and has coverage of a micro cell scale.

HeNB (Home eNodeB): A base station of an EPS network. The HeNB isinstalled indoors and has coverage of a micro cell scale.

MME (Mobility Management Entity): A network node of the EPS networkperforming functions of Mobility Management (MM) and Session Management(SM).

PDN-GW (Packet Data Network-Gateway)/PGW/P-GW: A network node of the EPSnetwork performing functions of UE IP address allocation, packetscreening and filtering, and charging data collection.

SGW (Serving Gateway)/S-GW: A network node of the EPS network performingfunctions of mobility anchor, packet routing, idle mode packetbuffering, and triggering of the MME paging the UE.

PCRF (Policy and Charging Rule Function): A network node of the EPSnetwork making a policy decision for dynamically applying adifferentiated QoS and charging policy on a service flow basis.

OMA DM (Open Mobile Alliance Device Management): A protocol designed formanagement of mobile devices such as a cellular phone, a PDA, and aportable computer, that performs functions of device configuration,firmware upgrade, and error report.

OAM (Operation Administration and Maintenance): A group of networkmanagement functions that provides network defect indication,performance information, and data and diagnosis functions.

NAS (Non-Access Stratum): An upper stratum of a control plane betweenthe UE and the MME. The NAS is a functional layer for signaling betweena UE and a core network and exchange of a traffic message between the UEand the core network in LTE/UMTS protocol stack. The NAS mainlyfunctions to support UE mobility and a session management procedure forestablishing and maintaining IP connection between a UE and a PDN GW.

EMM (EPS Mobility Management): A sub-layer of a NAS layer, that may bein either an “EMM-Registered” or “EMM-Deregistered” state depending onwhether a UE is attached to or detached from a network.

ECM (EMM Connection Management) connection: A signaling connection forexchange of a NAS message, established between the UE and an MME. TheECM connection is a logical connection consisting of an RRC connectionbetween the UE and an eNB and an SI signaling connection between the eNBand the MME. If the ECM connection is established/terminated, the RRCconnection and the S1 signaling connection are allestablished/terminated as well. To the UE, an established ECM connectionmeans having an RRC connection established with the eNB and, to the MME,the established ECM connection means having an S1 signaling connectionestablished with the eNB. Depending on whether a NAS signalingconnection, i.e., the ECM connection, is established, ECM may be ineither “ECM-Connected” or “ECM-Idle” state.

AS (Access-Stratum): This includes a protocol stack between the UE and awireless (or access) network and is in charge of data and networkcontrol signal transmission.

NAS configuration MO (Management Object): An MO used in the process ofconfiguring parameters related to NAS functionality for the UE.

PDN (Packet Data Network): A network where a server (e.g., an MMS(Multimedia Messaging Service) server, a WAP (Wireless ApplicationProtocol) server, etc.) supporting a specific service is located.

PDN connection: A logical connection between a PDN and a UE representedby one IP address (one IPv4 address and/or one IPv6 prefix).

APN (Access Point Name): A text sequence for indicating or identifying aPDN. A requested service or network is accessed through a specific P-GW.The APN means a predefined name (text sequence) in a network so as todiscover this P-GW. (e.g., internet.mnc012.mcc345.gprs).

RAN (Radio Access Network): A unit including a NodeB, an eNodeB and anRNC (Radio Network Controller) for controlling the NodeB and the eNodeBin a 3GPP network. The RAN is present between UEs and providesconnection to the core network.

MLR (Home Location Register)/HSS(Home Subscriber Server): A databasecontaining subscriber information of a 3GPP network. The HSS can performfunctions such as configuration storage, identity management and userstate storage.

PLMN (Public Land Mobile Network): A network configured for the purposeof providing mobile communication services to individuals. This networkcan be configured per operator.

ANDSF (Access Network Discovery and Selection Function): One networkentity that provides a policy to discover and select access that the UEcan use with respect to each service provider.

EPC path (or infrastructure data path): A user plane communication paththrough an EPC.

E-RAB (E-UTRAN Radio Access Bearer): Concatenation of an S1 bearer and adata radio bearer corresponding to the S1 bearer. If the E-RAB ispresent, there is one-to-one mapping between the E-RAB and an EPS bearerof a NAS.

GTP (GPRS Tunneling Protocol): A group of IP-based communicationprotocols used to carry a general packet radio service (GPRS) withinGSM, UMTS, and LTE networks. In 3GPP architectures, GTP and proxy mobileIPv6 based interfaces are specified on various interface points. The GTPcan be decomposed into some protocols (e.g., GTP-C, GTP-U, and GTP').GTP-C is used within a GPRS core network for signaling between gatewayGPRS support nodes (GGSN) and serving GPRS support nodes (SGSN). GTP-Callows the SGSN to activate a session on a user's behalf (e.g., PDNcontext activation), deactivate the same session, adjust quality ofservice parameters, or update a session for a subscriber that has justarrived from another SGSN. GTP-U is used to carry user data within theGPRS core network and between a radio access network and a core network.

Proximity service (or ProSe service or proximity based service): Aservice for enabling discovery and mutual direct communication,communication via an eNB, or communication via a third device, betweenphysically adjacent devices. In this case, user plane data is exchangedthrough a direct data path without passing through a 3GPP core network(e.g., EPC).

ProSe communication: Communication through a ProSe communication pathbetween two or more ProSe-enabled UEs. Unless mentioned otherwise, ProSecommunication means one of ProSe E-UTRA communication, ProSe-assistedWLAN direct communication between two UEs, ProSe group communication,and ProSe broadcast communication.

ProSe E-UTRA communication: ProSe communication using a ProSe E-UTRAcommunication path.

ProSe-assisted WLAN direct communication: ProSe communication using adirect communication path.

ProSe communication path: A communication path supporting ProSecommunication. A ProSe E-UTRA communication path may be establishedbetween ProSe-enabled UEs or through a local eNB, using E-UTRA. AProSe-assisted WLAN direct communication path may be directlyestablished between ProSe-enabled UEs, using a WLAN.

EPC path (or infrastructure data path): A user plane communication paththrough an EPC.

ProSe discovery: A process of identifying/confirming adjacentProSe-enabled UEs, using E-UTRA.

ProSe group communication: One-to-multi ProSe communication using acommon communication path, between two or more adjacent ProSe-enabledUEs.

ProSe UE-to-network relay: A ProSe-enabled public safety UE operating asa communication relay between a ProSe-enabled network and aProSe-enabled UE, using E-UTRA.

Remote UE: A ProSe-enabled UE connected to an EPC network through theProSe UE-to-network relay, i.e., communicating through a PDN, withoutbeing serviced by an E-UTRAN.

FIG. 1 is a schematic diagram showing the structure of an evolved packetsystem (EPS) including an evolved packet core (EPC).

The EPC is a core element of system architecture evolution (SAE) forimproving performance of 3GPP technology. SAE corresponds to a researchproject for determining a network structure supporting mobility betweenvarious types of networks. For example, SAE aims to provide an optimizedpacket-based system for supporting various radio access technologies andproviding an enhanced data transmission capability.

Specifically, the EPC is a core network of an IP mobile communicationsystem for 3GPP LTE and can support real-time and non-real-timepacket-based services. In conventional mobile communication systems(i.e. second-generation or third-generation mobile communicationsystems), functions of a core network are implemented through acircuit-switched (CS) sub-domain for voice and a packet-switched (PS)sub-domain for data. However, in a 3GPP LTE system which is evolved fromthe third generation communication system, CS and PS sub-domains areunified into one IP domain. That is, In 3GPP LTE, connection ofterminals having IP capability can be established through an IP-basedbusiness station (e.g., an eNodeB (evolved Node B)), EPC, and anapplication domain (e.g., IMS). That is, the EPC is an essentialstructure for end-to-end IP services.

The EPC may include various components. FIG. 1 shows some of thecomponents, namely, a serving gateway (SGW), a packet data networkgateway (PDN GW), a mobility management entity (MME), a serving GPRS(general packet radio service) supporting node (SGSN) and an enhancedpacket data gateway (ePDG).

The SGW (or S-GW) operates as a boundary point between a radio accessnetwork (RAN) and a core network and maintains a data path between aneNodeB and the PDN GW. When. When a terminal moves over an area servedby an eNodeB, the SGW functions as a local mobility anchor point. Thatis, packets. That is, packets may be routed through the SGW for mobilityin an evolved UMTS terrestrial radio access network (E-UTRAN) definedafter 3GPP release-8. In addition, the SGW may serve as an anchor pointfor mobility of another 3GPP network (a RAN defined before 3GPPrelease-8, e.g., UTRAN or GERAN (global system for mobile communication(GSM)/enhanced data rates for global evolution (EDGE) radio accessnetwork).

The PDN GW (or P-GW) corresponds to a termination point of a datainterface for a packet data network. The PDN GW may support policyenforcement features, packet filtering and charging support. Inaddition, the PDN GW may serve as an anchor point for mobilitymanagement with a 3GPP network and a non-3GPP network (e.g., anunreliable network such as an interworking wireless local area network(I-WLAN) and a reliable network such as a code division multiple access(CDMA) or WiMax network.

Although the SGW and the PDN GW are configured as separate gateways inthe example of the network structure of FIG. 1, the two gateways may beimplemented according to a single gateway configuration option.

The MME performs signaling and control functions for supporting accessof a UE for network connection, network resource allocation, tracking,paging, roaming and handover. The MME controls control plane functionsassociated with subscriber and session management. The MME managesnumerous eNodeBs and signaling for selection of a conventional gatewayfor handover to other 2G/3G networks. In addition, the MME performssecurity procedures, terminal-to-network session handling, idle terminallocation management, etc.

The SGSN handles all packet data such as mobility management andauthentication of a user for other 3GPP networks (e.g., a GPRS network).

The ePDG serves as a security node for a non-3GPP network (e.g., anI-WLAN, a Wi-Fi hotspot, etc.).

As described above with reference to FIG. 1, a terminal having IPcapabilities may access an IP service network (e.g., an IMS) provided byan operator via various elements in the EPC not only based on 3GPPaccess but also on non-3GPP access.

Additionally, FIG. 1 shows various reference points (e.g. S1-U, S1-MME,etc.). In 3GPP, a conceptual link connecting two functions of differentfunctional entities of an E-UTRAN and an EPC is defined as a referencepoint. Table 1 is a list of the reference points shown in FIG. 1.Various reference points may be present in addition to the referencepoints in Table 1 according to network structures.

TABLE 1 Reference Point Description S1-MME Reference point for thecontrol plane protocol between E-UTRAN and MME. S1-U Reference pointbetween E-UTRAN and Serving GW for the per bearer user plane tunnelingand inter eNB path switching during handover. S3 It enables user andbearer information exchange for inter 3GPP access network mobility inidle and/or active state. This reference point can be used intra-PLMN orinter-PLMN (e.g. in the case of Inter-PLMN HO). S4 It provides relatedcontrol and mobility support between GPRS Core and the 3GPP Anchorfunction of Serving GW. In addition, if Direct Tunnel is notestablished, it provides the user plane tunneling. S5 It provides userplane tunneling and tunnel management between Serving GW and PDN GW. Itis used for Serving GW relocation due to UE mobility and if the ServingGW needs to connect to a non-collocated PDN GW for the required PDNconnectivity. S11 Reference point between MME and Serving GW. SGi It isthe reference point between the PDN GW and the packet data network.Packet data network may be an operator exter- nal public or privatepacket data network or an intra oper- ator packet data network, e.g. forprovision of IMS services. This reference point corresponds to Gi for3GPP accesses.)

Among the reference points shown in FIG. 1, S2 a and S2 b correspond tonon-3GPP interfaces. S2 a is a reference point which provides reliablenon-3GPP access and related control and mobility support between PDN GWsto a user plane. S2 b is a reference point which provides relatedcontrol and mobility support between the ePDG and the PDN GW to the userplane.

FIG. 2 is a diagram exemplarily illustrating architectures of a typicalE-UTRAN and EPC.

As shown in the figure, while radio resource control (RRC) connection isactivated, an eNodeB may perform routing to a gateway, schedulingtransmission of a paging message, scheduling and transmission of abroadcast channel (BCH), dynamic allocation of resources to a UE onuplink and downlink, configuration and provision of eNodeB measurement,radio bearer control, radio admission control, and connection mobilitycontrol. In the EPC, paging generation, LTE_IDLE state management,ciphering of the user plane, SAE bearer control, and ciphering andintegrity protection of NAS signaling.

FIG. 3 is a diagram exemplarily illustrating the structure of a radiointerface protocol in a control plane between a UE and an eNB, and FIG.4 is a diagram exemplarily illustrating the structure of a radiointerface protocol in a user plane between the UE and the eNB.

The radio interface protocol is based on the 3GPP wireless accessnetwork standard. The radio interface protocol horizontally includes aphysical layer, a data link layer, and a networking layer. The radiointerface protocol is divided into a user plane for transmission of datainformation and a control plane for delivering control signaling whichare arranged vertically.

The protocol layers may be classified into a first layer (L1), a secondlayer (L2), and a third layer (L3) based on the three sublayers of theopen system interconnection (OSI) model that is well known in thecommunication system.

Hereinafter, description will be given of a radio protocol in thecontrol plane shown in FIG. 3 and a radio protocol in the user planeshown in FIG. 4.

The physical layer, which is the first layer, provides an informationtransfer service using a physical channel. The physical channel layer isconnected to a medium access control (MAC) layer, which is a higherlayer of the physical layer, through a transport channel. Data istransferred between the physical layer and the MAC layer through thetransport channel. Transfer of data between different physical layers,i.e., a physical layer of a transmitter and a physical layer of areceiver is performed through the physical channel.

The physical channel consists of a plurality of subframes in the timedomain and a plurality of subcarriers in the frequency domain. Onesubframe consists of a plurality of symbols in the time domain and aplurality of subcarriers. One subframe consists of a plurality ofresource blocks. One resource block consists of a plurality of symbolsand a plurality of subcarriers. A Transmission Time Interval (TTI), aunit time for data transmission, is 1 ms, which corresponds to onesubframe.

According to 3GPP LTE, the physical channels present in the physicallayers of the transmitter and the receiver may be divided into datachannels corresponding to Physical Downlink Shared Channel (PDSCH) andPhysical Uplink Shared Channel (PUSCH) and control channelscorresponding to Physical Downlink Control Channel (PDCCH), PhysicalControl Format Indicator Channel (PCFICH), Physical Hybrid-ARQ IndicatorChannel (PHICH) and Physical Uplink Control Channel (PUCCH).

The second layer includes various layers. First, the MAC layer in thesecond layer serves to map various logical channels to various transportchannels and also serves to map various logical channels to onetransport channel. The MAC layer is connected with an RLC layer, whichis a higher layer, through a logical channel. The logical channel isbroadly divided into a control channel for transmission of informationof the control plane and a traffic channel for transmission ofinformation of the user plane according to the types of transmittedinformation.

The radio link control (RLC) layer in the second layer serves to segmentand concatenate data received from a higher layer to adjust the size ofdata such that the size is suitable for a lower layer to transmit thedata in a radio interval.

The Packet Data Convergence Protocol (PDCP) layer in the second layerperforms a header compression function of reducing the size of an IPpacket header which has a relatively large size and contains unnecessarycontrol information, in order to efficiently transmit an IP packet suchas an IPv4 or IPv6 packet in a radio interval having a narrow bandwidth.In addition, in LTE, the PDCP layer also performs a security function,which consists of ciphering for preventing a third party from monitoringdata and integrity protection for preventing data manipulation by athird party.

The Radio Resource Control (RRC) layer, which is located at theuppermost part of the third layer, is defined only in the control plane,and serves to configure radio bearers (RBs) and control a logicalchannel, a transport channel, and a physical channel in relation toreconfiguration and release operations. The RB represents a serviceprovided by the second layer to ensure data transfer between a UE andthe E-UTRAN.

If an RRC connection is established between the RRC layer of the UE andthe RRC layer of a wireless network, the UE is in the RRC Connectedmode. Otherwise, the UE is in the RRC Idle mode.

Hereinafter, description will be given of the RRC state of the UE and anRRC connection method. The RRC state refers to a state in which the RRCof the UE is or is not logically connected with the RRC of the E-UTRAN.The RRC state of the UE having logical connection with the RRC of theE-UTRAN is referred to as an RRC_CONNECTED state. The RRC state of theUE which does not have logical connection with the RRC of the E-UTRAN isreferred to as an RRC_IDLE state. A UE in the RRC_CONNECTED state hasRRC connection, and thus the E-UTRAN may recognize presence of the UE ina cell unit. Accordingly, the UE may be efficiently controlled. On theother hand, the E-UTRAN cannot recognize presence of a UE which is inthe RRC_IDLE state. The UE in the RRC_IDLE state is managed by a corenetwork in a tracking area (TA) which is an area unit larger than thecell. That is, for the UE in the RRC_IDLE state, only presence orabsence of the UE is recognized in an area unit larger than the cell. Inorder for the UE in the RRC_IDLE state to be provided with a usualmobile communication service such as a voice service and a data service,the UE should transition to the RRC_CONNECTED state. A TA isdistinguished from another TA by a tracking area identity (TAI) thereof.A UE may configure the TAI through a tracking area code (TAC), which isinformation broadcast from a cell.

When the user initially turns on the UE, the UE searches for a propercell first. Then, the UE establishes RRC connection in the cell andregisters information thereabout in the core network. Thereafter, the UEstays in the RRC_IDLE state. When necessary, the UE staying in theRRC_IDLE state selects a cell (again) and checks system information orpaging information. This operation is called camping on a cell. Onlywhen the UE staying in the RRC_IDLE state needs to establish RRCconnection, does the UE establish RRC connection with the RRC layer ofthe E-UTRAN through the RRC connection procedure and transition to theRRC_CONNECTED state. The UE staying in the RRC_IDLE state needs toestablish RRC connection in many cases. For example, the cases mayinclude an attempt of a user to make a phone call, an attempt totransmit data, or transmission of a response message after reception ofa paging message from the E-UTRAN.

The non-access stratum (NAS) layer positioned over the RRC layerperforms functions such as session management and mobility management.

Hereinafter, the NAS layer shown in FIG. 3 will be described in detail.

The ESM (Evolved Session Management) belonging to the NAS layer performsfunctions such as default bearer management and dedicated bearermanagement to control a UE to use a PS service from a network.. The UEis assigned a default bearer resource by a specific packet data network(PDN) when the UE initially accesses the PDN. In this case, the networkallocates an available IP to the UE to allow the UE to use a dataservice. The network also allocates QoS of a default bearer to the UE.LTE supports two kinds of bearers. One bearer is a bearer havingcharacteristics of guaranteed bit rate (GBR) QoS for guaranteeing aspecific bandwidth for transmission and reception of data, and the otherbearer is a non-GBR bearer which has characteristics of best effort QoSwithout guaranteeing a bandwidth. The default bearer is assigned to anon-GBR bearer. The dedicated bearer may be assigned a bearer having QoScharacteristics of GBR or non-GBR.

A bearer allocated to the UE by the network is referred to as an evolvedpacket service (EPS) bearer. When the EPS bearer is allocated to the UE,the network assigns one ID. This ID is called an EPS bearer ID. One EPSbearer has QoS characteristics of a maximum bit rate (MBR) and/or aguaranteed bit rate (GBR).

The UE requested PDN connectivity procedure is for a UE to request thesetup of a default EPS bearer to a PDN. The UE requests connectivity toa PDN by sending a PDN connectivity request message to the network. Ifaccepted by the network, this procedure initiates the establishment of adefault EPS bearer context. If EMM-REGISTERED without PDN connection isnot supported by the UE or the MME, for the UE having no PDN connection,the procedure is used either to establish the first default bearer byincluding the PDN connectivity request message into the initial attachmessage. Otherwise, the procedure is used to establish subsequentdefault bearers to additional PDNs in order to allow the UE simultaneousaccess to multiple PDNs by sending the message stand-alone. IfEMM-REGISTERED without PDN connection is supported by the UE and theMME, the procedure is used to establish the first or subsequent defaultbearers to a PDN or additional PDNs by sending the PDN connectivityrequest message stand-alone.

When the PDN connectivity request message is sent together with anattach request message, the UE may not include the APN. In order torequest connectivity to a PDN using the default APN, the UE includes theaccess point name IE in the PDN connectivity request message or, whenapplicable, in the ESM information response message, according tospecific conditions. In order to request connectivity to an additionalPDN using a specific APN, the UE includes the requested APN in the PDNrequest message.

FIG. 5 illustrates LTE protocol stacks for a user plane and a controlplane. FIG. 5(a) illustrates user plane protocol stacks overUE-eNB-SGW-PGW-PDN and FIG. 5(b) illustrates control plane protocolstacks over UE-eNB-MME-SGW-PGW. Functions of key layers of the protocolstacks will now be briefly described below.

Referring to FIG. 5(a), a GTP-U protocol is used to forward user IPpackets over an S1-U/S5/X2 interface. If a GTP tunnel is established toforward data during LTE handover, an end marker packet is transferred tothe GTP tunnel as the last packet.

Referring to FIG. 5(b), an S1-AP protocol is applied to an S1-MMEinterface. The S1 -AP protocol supports functions such as S1 interfacemanagement, E-RAB management, NAS signaling delivery, and UE contextmanagement. The S1-AP protocol transfers an initial UE context to theeNB in order to set up E-RAB(s) and then manages modification or releaseof the UE context. A GTP-C protocol is applied to S11/S5 interfaces. TheGTP-C protocol supports exchange of control information for generation,modification, and termination of GTP tunnel(s). The GTP-C protocolgenerates data forwarding tunnels in the case of LTE handover.

A description of the protocol stacks and interfaces illustrated in FIGS.3 and 4 is applicable to the same protocol stacks and interfacesillustrated in FIG. 5.

FIG. 6 is a flowchart illustrating a random access procedure in 3GPPLTE.

The random access procedure is used for a UE to obtain ULsynchronization with a base station or to be assigned a UL radioresource.

The UE receives a root index and a physical random access channel(PRACH) configuration index from an eNB. Each cell has 64 candidaterandom access preambles defined by a Zadoff-Chu (ZC) sequence. The rootindex is a logical index used for the UE to generate 64 candidate randomaccess preambles.

Transmission of a random access preamble is limited to a specific timeand frequency resources for each cell. The PRACH configuration indexindicates a specific subframe and preamble format in which transmissionof the random access preamble is possible.

The random access procedure, in particular, a contention-based randomaccess procedure, includes the following three steps. Messagestransmitted in the following steps 1, 2, and 3 are referred to as msg1,msg2, and msg4, respectively.

1. The UE transmits a randomly selected random access preamble to theeNodeB. The UE selects a random access preamble from among 64 candidaterandom access preambles and the UE selects a subframe corresponding tothe PRACH configuration index. The UE transmits the selected randomaccess preamble in the selected subframe.

2. Upon receiving the random access preamble, the eNB sends a randomaccess response (RAR) to the UE. The RAR is detected in two steps.First, the UE detects a PDCCH masked with a random access (RA)-RNTI. TheUE receives an RAR in a MAC (medium access control) PDU (protocol dataunit) on a PDSCH indicated by the detected PDCCH. The RAR includestiming advance (TA) information indicating timing offset information forUL synchronization, UL resource allocation information (UL grantinformation), and a temporary UE identifier (e.g., a temporary cell-RNTI(TC-RNTI)).

3. The UE may perform UL transmission according to resource allocationinformation (i.e., scheduling information) and a TA value in the RAR.HARQ is applied to UL transmission corresponding to the RAR.Accordingly, after performing UL transmission, the UE may receivereception response information (e.g., a PHICH) corresponding to ULtransmission.

FIG. 7 illustrates a connection procedure in a radio resource control(RRC) layer.

As shown in FIG. 7, the RRC state is set according to whether or not RRCconnection is established. An RRC state indicates whether or not anentity of the RRC layer of a UE has logical connection with an entity ofthe RRC layer of an eNB. An RRC state in which the entity of the RRClayer of the UE is logically connected with the entity of the RRC layerof the eNB is called an RRC connected state. An RRC state in which theentity of the RRC layer of the UE is not logically connected with theentity of the RRC layer of the eNB is called an RRC idle stat.

A UE in the Connected state has RRC connection, and thus the E-UTRAN mayrecognize presence of the UE in a cell unit. Accordingly, the UE may beefficiently controlled. On the other hand, the eNB cannot recognizepresence of a UE which is in the idle state. The UE in the idle state ismanaged by the core network in a tracking area unit which is an areaunit larger than the cell. The tracking area is a unit of a set ofcells. That is, for the UE which is in the idle state, only presence orabsence of the UE is recognized in a larger area unit. In order for theUE in the idle state to be provided with a usual mobile communicationservice such as a voice service and a data service, the UE shouldtransition to the connected state.

When the user initially turns on the UE, the UE searches for a propercell first, and then stays in the idle state. Only when the UE stayingin the idle state needs to establish RRC connection, does the UEestablish RRC connection with the RRC layer of the eNB through the RRCconnection procedure and then transition to the RRC connected state.

The UE staying in the idle state needs to establish RRC connection inmany cases. For example, the cases may include an attempt of a user tomake a phone call, an attempt to transmit data, or transmission of aresponse message after reception of a paging message from the E-UTRAN.

In order for the UE in the idle state to establish RRC connection withthe eNodeB, the RRC connection procedure needs to be performed asdescribed above. The RRC connection procedure is broadly divided intotransmission of an RRC connection request message from the

UE to the eNB, transmission of an RRC connection setup message from theeNB to the UE, and transmission of an RRC connection setup completemessage from the UE to eNB, which are described in detail below withreference to FIG. 7.

1. When the UE in the idle state desires to establish RRC connection forreasons such as an attempt to make a call, a data transmission attempt,or a response of the eNB to paging, the UE transmits an RRC connectionrequest message to the eNB first.

2. Upon receiving the RRC connection request message from the UE, theeNB accepts the RRC connection request of the UE when the radioresources are sufficient, and then transmits an RRC connection setupmessage, which is a response message, to the UE.

3. Upon receiving the RRC connection setup message, the UE transmits anRRC connection setup complete message to the eNB.

Only when the UE successfully transmits the RRC connection setupcomplete message, does the UE establish RRC connection with the eNB andtransition to the RRC connected mode.

In order for the UE of an idle state to transition to an activationstate in which traffic transmission/reception can be performed due tooccurrence of new traffic, a service request procedure is performed. Iftraffic to be transmitted by the UE occurs or traffic to be transmittedto the UE by a network occurs in a state in which the UE is registeredwith the network but an S1 connection is released and a wirelessresource is not allocated to the UE due to traffic inactivation, i.e.,in a state in which the UE is in an EMM registered state(EMM-Registered) but is in an ECM-Idle state, the UE requests that thenetwork provide a service. Upon successfully completing the servicerequest process, the UE transitions to an ECM connected state(ECM-Connected) and configures an ECM connection (RRC connection+S1signaling connection) in a control plane and an E-RAB (a data radiobearer (DRB) and an S1 bearer) in a user plane, therebytransmitting/receiving traffic. If the network desires to transfertraffic to the UE of an ECM idle state (ECM-Idle), the network informsthe UE, through a paging message, that there is traffic to betransmitted so that the UE may request that the network provide aservice.

FIG. 8 is a diagram illustrating a vehicle-to-everything (V2X)communication environment.

If a vehicle accident happens, significant injury and property damagemay occur. Therefore, demand for technology capable of guaranteeingsafety of pedestrians as well as safety of people riding in a vehicle isincreasing. Thus, technology based on hardware and software specializedfor a vehicle has been incorporated into the vehicle.

LTE based V2X communication technology evolved from 3GPP shows a trendof incorporating information technology (IT) into the vehicle. Aconnectivity function is applied to some vehicle models and a studysupporting vehicle-to-vehicle (V2V) communication,vehicle-to-infrastructure (V2I) communication, vehicle-to-pedestrian(V2P) communication, and vehicle-to-network (V2N) communication hascontinued due to evolution of a communication function.

According to V2X communication, a vehicle continues to broadcastinformation about the location, velocity, and direction thereof. Acontiguous vehicle that has received the broadcast information uses theinformation for the purpose of accident prevention by recognizingmovement of vehicles therearound.

That is, similar to the case in which a person possesses a UE such as asmartphone or a smartwatch, a vehicle also mounts a UE of a specifictype therein. In this case, the UE mounted in the vehicle is a device towhich an actual communication service is provided by a communicationnetwork. For example, the UE mounted in the vehicle may be connected toan eNB in an E-UTRAN and receive a communication service.

However, there are many considerations to implement V2X communication inthe vehicle because astronomical costs are consumed to install trafficsafety infrastructure such as a V2X eNB. That is, in order to supportV2X communication on all roads on which vehicles can move, hundreds ofthousands of V2X eNBs should be installed. In addition, since eachnetwork node accesses the Internet or a central control server on awired network basis for the purpose of stable communication with aserver, a wired network should be installed and installation andmaintenance costs of the wired network are high.

To effectively support V2X in an LTE or EPS system, QoS optimized fordata generated in a V2X application needs to be provided.

A message for a V2X service includes a message that a UE periodicallytransmits and a message that the UE transmits upon occurrence of aspecific event. For use cases and characteristics of these messages,reference is made to 3GPP TR 22.885. In addition, various ITS relateduse cases and V2X messages are defined in ETSI. For example, messages ofa co-operative awareness message (CAM) type and messages of adecentralized environmental notification message (DENM) type and usecases of these messages are defined in ETS1 ITS.

The V2X messages should be received by all UEs in a region (range)within which the messages are valid in terms of road safety. As such,the V2X messages may be transmitted using a broadcast scheme such asmultimedia broadcast multicast services (MBMS) or single-cellpoint-to-multipoint (SC-PTM). For an evolved MBMS (eMBMS) architecturefor the V2X service, refer to 3GPP TR 23.785. A new function called aV2X application server (V2X AS) and reference points such as VC1, VMB2,and LTE-Uu are defined in the eMBMS architecture for the V2X service.The V2X AS is the logical function that is used for network relatedactions required for V2X. It is similar to the Group CommunicationSystem Application Server (GCS AS). The VC1 is the reference pointbetween the V2X AS and the application client on the UE, the VMB2 is thereference point between the V2X AS and the BM-SC, and the LTE-Uu thereference point between the V2X enabled UE and the E-UTRAN. For detailsof the MBMS, refer to 3GPP TS 23.246, 3GPP TS 23.468, or 3GPP TS 36.300.

FIG. 9 illustrates V2X message transmission/reception for a V2V/V2Pservice via an LTE-Uu.

Section 6.3 of 3GPP TR 23.785 v0.2.0 defines a V2X messagetransmission/reception related solution for LTE-Uu based V2V and V2Pservices. Transmission/reception of a V2X message based on the LTE-Uu(e.g., defined in 3GPP TS 22.185) needs to satisfy predetermined latencyrequirements.

A UE may transmit the V2X message via the LTE-Uu and the V2X message maybe forwarded to a plurality of UEs over the LTE-Uu as illustrated inFIG. 9.

FIG. 10 illustrates a V2X message transmission/reception procedure for aV2V/V2P service via an LTE-Uu.

1. UE obtains necessary information for MBMS reception of V2X messagefor V2V/P Services.

2. UE-1 sends a V2X message over LTE-Uu. UE-1 has already established aSelective IP Traffic Offload (SIPTO) at the local network PDN connectionto transmit the V2X message for V2V/P Services over LTE-Uu as describedin TS 23.401. The eNB receives the V2X message and the V2X message isrouted to the V2X Application Server via S-GW/L-GW.

3. The V2X Application Server decides to forward the V2X message and thetarget area of the message. The V2X Application Server sends the V2Xmessage to the target area of the message by MBMS delivery. The MBMSbearer used for MBMS delivery can be pre-established.

Meanwhile, in Europe or the US, there are privacy issues. With regard tothe privacy issues in Europe or the US, a current LTE-Uu based V2Xsystem or a V2X system using an MBMS function has privacy issuesdescribed below.

Changing UE's identity overly frequently is not necessary and couldcause the fast exhaustion of the identity space. V2X securityrequirement does allow UE being trackable in a short time scale, e.g. afew minutes. For example, some tracking of a vehicle UE by other vehicleUEs nearby is necessary to run V2X application algorithms that predictthe trajectory of vehicles. User privacy is concerned with longer timescale, e.g. during a journey from home to the work place, etc.

Within the V2V messages that each UE sends, there is some uniquelyidentifiable information, e.g. the temporary ID in the BSM blob, the L2ID when PC5 is used, the IP address and EPS identifiers when LTE-Uu isused. These identifiers together with the location information withinthe V2X message can be used to track a UE. In FIG. 1 this is illustratedby showing vehicle trajectories (along a road) in different colors,where the color is unchanged for a short time period. In order to makecorrelation between consecutive short-time-periods difficult, theuniquely identifiable information has to change for all UEs at one exacttime instance. Otherwise, if only a single UE changes the identifiers,the system will still be able to link the UE before and after thechange.

However, for LTE-Uu based V2X, the UE exchanges message with V2XApplication Server (hereinafter, V2X App Server or V2X AS) via LTEsystem. Therefore, it may result in the need for introducing new UEidentifiers that hide the 3GPP identity from other UEs and the networkitself (e.g. V2X App Server). For LTE-Uu based V2X, the traffic goesthrough the V2X App Server, before it is forwarded to the other UEs.Therefore, the system must make sure that the V2X App Server hides thesource UE identity. However, for LTE-Uu based V2X, it implies that UEidentifiable information should change periodically so as not to allowlonger-term tracking by the network or the V2X application server orother UEs. This would have significant network architecture impacts.

From the perspective of meeting the requirement that the network willnot be able to track individual UEs, we make the following observations:

1. The V2X message contents are visible to the network and the 3rd partyentity, e.g. V2X AS, since the messages cannot be encrypted. Thismessages provides precise location of the UE.

2. Since traffic is traversing the network, the PLMNs involved may beable to track UEs based on their 3GPP identities (e.g. IMSI, TMS1 etc.).

3. The network/3rd Party can track the UE based IP address of UEbecause:

The uplink traffic is sent to the V2X AS using the IP address allocatedby the LTE network.

If the IP address does not change, V2X AS could derive the UE's pathhistory using the contents of V2X message and the long lasting IPaddress.

4. When the identity needs to be rolled, all of the UE's identities andaddresses need to change as well, otherwise, the network would be ableto track the UE. These identifies include:

Application-layer identifiable information in the V2V message (e.g. keyused to sign safety messages);

Transport layer identifier, e.g. IP addresses;

Identity used to establish the EPS connectivity (e.g. IMSI, TMSI);and/or

Radio Layer identifier, e.g. the C-RNTI.

If a UE has regular user traffic on the Uu interface being transferredin parallel to the V2X traffic, these two types of traffic may becorrelated. Therefore, the EPS connection used for the V2X communicationshould not be shared with any other applications (that does not have thesame security requirements as V2X), and this applies to all theidentifiers used for this EPS connection.

In consideration of the privacy issues present in the LTE-Uu based V2Xsystem or the V2X system using the MBMS function, the present inventionproposes a vehicle using V2X communication and methods for guaranteeingprivacy of a user of a vehicle using V2X communication. Hereinafter, aV2X UE may also be referred to as a V-UE.

<Likability of IP Address to Vehicle Identity>

For the V2X AS to link an identified IP address to a specific vehicle,following condition should be met:

Regardless of whether the IP address of each V-UE is assigned by oneco-ordinating node or by each V-UE itself each V-UE uses a distinct IPaddress.

Otherwise, if V-UE I and V-UE 2 use same IP address, the V2X AS cannotrelate an application layer identity with the IP address. Especially, ifV-UE 3 changes the self-assigned IP address and the application layeridentity simultaneously from (IP A, App ID 1) to (IP B, App ID 2), theV2X AS cannot know whether (IP B, App ID 2) is used by existing V-UE 3or by new V-UE 4 which just switched on its V2X module.

For Non-IP type message such as CAM(Co-operative Awarenessmessage)/DENM(Decentralized Environmental NotificationMessage)/BSM(Basic Safety Message): Since an IP based network uses aP/L-GW up to a V2X AS, the CAM/DENM/BSM should be encapsulated into anadditional protocol layer, for example, an IP. If all non-IP typemessages generated by different V-UEs are bundled into one flow betweenthe P/L-GW and the V2X AS, since the relationship between an IP addressand a V-UE is formed as 1: N correspondence rather than 1: 1correspondence, there is no way for the V2X AS to individually trackeach V-UE based on the IP address. In fact, even when a separate flow isused up to a P/L-GW duration by each V-UE, the P/L-GW may randomlychange an IP address of an IP protocol header at any time.

For IP messages: It may be assumed that LTE V2X uses a separate PDN/APNonly for LTE V2X. It may be also assumed that a specific V2X AS isallocated to a different PDN/APN for LTE V2X. Then, all the IP messagesreceived by the L/P-GW from V-UEs can be forwarded to the specific V2XAS. Because safety V2X messages are meant to be received by any V-UE,there is no need to support the case where V2X messages from V2X AS isdelivered to the specific V-UE. Then, allocating same IP address to allV-UEs belonging to same PDN/APV for LTE V2X does not cause any problem.

In actuality, a current assumption in system architecture stage 2 (SA2)for LTE-Uu based V2X is that any V2X service is implemented by aplurality of V2X ASs, each V2X AS provides a service to a specific area,and, in this process, the respective V2X ASs provide a communicationfunction by a combination of nodes providing different MBMS functions.In this case, the combination of the nodes providing the MBMS functionsmean a combination of eNBs, MMEs, MCEs, MBMS-GWs, and L-GWs. Forexample, when a vehicle moves from area A to area B, the UE receives aservice by an L-GW M in the area A and receives a service by anotherL-GW N in the area B. In addition, as the UE moves from the area A tothe area B, the UE communicates with V2X AS R connected to the L-GW Mand then communicates with V2X AS T connected to the L-GW N. That is, itis expected that a counterpart V2X AS of the UE will be replaced. Thisassumption seems to be realistic in consideration of the fact that anarea governed by each combination of MBMS functions and by the V2X ASmay not be that wide. For example, a vehicle driving in a city A willnot require V2X information generated in a city B. However, it isundesirable to cause a V-UE that has moved to a new area to find out anIP address of a new V2X AS behind an L-GW of the area because temporaryservice interruption which may occur while the V-UE finds out a new IPaddress in V2X communication is needed. In addition, upon consideringQoS, if data about safety and other data are mixed, since the data aboutsafety may affect QoS, traffic other than V2X may not be permitted in anAPN/PDN using LTE V2X. Accordingly, a link to a V2X AS related to anL-GW used for V2X to the L-GW may be regarded as nearly one-to-onecorrespondence under the consideration that different V2X ASs areconnected to respective L-GWs and there is no other non-V2X data. Then,IP addresses used by respective V-UEs are not important because alltraffic may be transferred only to a related V2X AS regardless of the IPaddresses.

The ITS application layer of V-UE just broadcast ITS message and doesnot care whether the message is received by other V-UEs over PC5interface or whether the message is received by V2X AS over Uuinterface. So, tunneling all V2X message received at P/L-GW from V-UEsto a specific V2X AS will not cause any issue. Then, making V-UE usewell-known IP address as source/destination IP address for V2X PDN is apotential way forward.

An operation according to the present invention will be described inmore detail hereinbelow.

An L-GW or a P-GW transmits UL data received thereby (i.e., transmittedby a UE) to a predesignated specific application server. If the UL datareceived by the L-GW or the P-GW is an IP message, the L-GW or the P-GWtransmits the data after changing a source IP address or a destinationIP address of the IP message to a specific value. The specific source IPaddress or destination IP address is pre-configured for the L-GW or theP-GW. If the preconfigured value is not present, an arbitrary value isused as the source IP address or the destination IP address.

If a UE is permitted to use a specific PDN/APN, the UE may select an IPaddress to be randomly used thereby. The PDN/APN may be a PDN/APNrelated to V2X.

A V-UE that desires to use a specific V2X service establishes PDNconnectivity for the specific V2X service and transmits a PDNconnectivity request to a network with respect to the PDN/APN mapped tothe specific V2X service in order to request that the network allocatean IP address corresponding to PDN connectivity. Upon receiving theconnectivity request for the specific PDN/APN from the V-UE, the networkmay allocate a predesignated value, for example, a specific IP addressvalue (as a source IP address). The predesignated value may be equal ormay be commonly used with respect to all UEs that have requestedconnectivity to the PDN/APN. For example, the UE may request that thenetwork allocate the IP address by transmitting the PDN connectivityrequest to the network. If the PDN connectivity request is related to aV2X PDN or APN, the network (e.g., P-GW or L-GW) may transmit a specificvalue identically or commonly allocated to all UEs belonging to thePDN/APN to the UE as an IP address. The PDN connectivity request mayinclude APN information defined for V2X. The network may allocate thesame IP address to all UEs that have transmitted the PDN connectivityrequest including the same APN information defined for V2X. As opposedto the case in which different IP addresses are allocated to differentUEs even for the same PDN/APN in a legacy system, the same IP address isallocated to all UEs that have transmitted the PDN connectivity requestfor a specific PDN/APN defined for V2X according to the presentinvention. Therefore, since UEs that have accessed the specific PDN/APNuse the same IP address, each vehicle cannot be tracked.

As another method, the UE may be designated so as to use a specific IPaddress with respect to a specific PDN/APN. For example, the network maytransmit, through a system information block (SIB) or an attachprocedure, IP information about an IP address that the UE should usewhen transmitting a message to the specific PDN/APN. Upon receiving theIP address information, the UE may use the IP address when transmittingdata to the PDN/APN. The IP address information may be transmitted tothe UE using a method such as open mobile alliance device management(OMA DM). Alternatively, the IP address information may be stored in asubscriber identity module (SIM). A UE with the IP address informationstored in the SIM may be introduced. Alternatively, if the IP address isallocated to the UE, the allocated IP address may be stored in the SIMof the UE. The network may inform the UE of whether to store the IPaddress allocated to the UE in the SIM. An IP address that should beused with respect to each application may be additionally designated tothe specific PDN/APN.

An IP address may be designated on an application basis without PDN/APNinformation. For example, when a V2X service is permitted to be used byany V-UE, the V-UE receives an SIB in a cell in which the V-UE resides.For example, the SIB may include information about a source IP10.10.10.10 and a destination IP 10.10.10.11 for application 1 andinformation about a source IP 101.101.101.101 and a destination IP101.101.101.111 for application 2. Upon receiving the SIB, if a messageto be transmitted by the UE is generated in application 1, the UE mayfill an IP header of data related to application 1 using the source IP10.10.10.10 and the destination IP 10.10.10.11 and, if a message to betransmitted by the UE is generated in application 2, the UE may fill anIP header of data related to application 2 using the sourceIP101.101.101.101 and the destination IP 101.101.101.111. Next, the UEtransmits the data. IP addresses may be notified through an OMA DMinstead of the SIB or IP address configuration information may be storedin the SIM.

Upon receiving the aforementioned IP information, the UE or the networknode operates as indicated by the information.

With respect to any V2X service data, in a process in which datagenerated by the UE is transferred to an L/P-GW, if the data transmittedby the UE does not include an IP protocol, the L/P-GW willunconditionally transmit the data to a specific V2X server because thereis no IP information. Accordingly, presence of a one-to-one link betweenthe P/L-GW and the V2X server may be considered. In this case, since alldata mapped to the V2X service will be transmitted to a designated V2XAS regardless of the UE, it is impossible for the V2X AS to track thedata as belonging to a specific UE by use of received data.Alternatively, in the above process, the L-GW will add an arbitrary IPaddress to the data received from the UE and then forward all traffic toa preset V2X server regardless of which UE has transmitted a message. Inthis case, it is impossible for the V2X AS to track the data asbelonging to a specific UE by use of the received data.

<Use of Other UE Instance for Other Traffic>

For Non-V2X service such as voice call or streaming service etc, theV-UE may use separate PDN/APN. This is already the case for the vehiclesavailable today installed with internet connectivity. For V2X, thesystem architecture stage 1 (SA1) technical specification (TS) hasfollowing requirements.

The E-UTRAN shall be capable of transferring messages via 3GPP networkentities between a UE and an application server both supporting V2Napplication with an end-to-end delay no longer than 1000 ms.

The 3GPP network shall provide a means for the mobile network operator(MNO) to authorize UEs supporting V2X application separately to performV2N communication.

From these requirements, it is clear that there are two types of V2Xdata, one for V2IN/P and one for V2N. V2N service is something thatvehicle equipped with Release 13 UE can use. One example is a navigationApp available today. From user perspective, it is the application usingnormal internet PDN which other general application also use. Also,considering the MBMS-based structure for LTE Uu-based V2X, V2X messagesover LTE-Uu are basically broadcast-type messages. Then, other V2Xmessage which basically non-broadcast type is transported over separatePDN. Based on these points, privacy issue is (?? does) not necessarilylead to multiple UE instances. Rather, using multiple PDNs for trafficof different characteristics/requirements are enough.

That is, the present invention proposes that a V2X message of abroadcast type and a V2X message of a non-broadcast type be transmittedthrough different channels. the present invention proposes that the V2Xmessage of the broadcast type and the V2X message of the non-broadcasttype be transmitted through different PDNs. The present inventionproposes that the V2X message of the broadcast type and the V2X messageof the non-broadcast type be transmitted through different APNs.

When the UE supports the V2X message, the UE may request a channelconfiguration for transmitting the message or requests a PDN/APNconfiguration. A PDN/APN value for the V2X message of the broadcast typemay be predesignated as a specific value. A PDN/APN value for the V2Xmessage of the non-broadcast type may be predesignated as a specificvalue.

For the present proposal, a network, a V2X service provider, or a V2Xapplication may provide the following information to the UE.

Information about a message of a broadcast property and/or informationabout a message of a non-broadcast property. Each of the message of thebroadcast property and the message of the non-broadcast property mayinclude information about a corresponding protocol and includeinformation about a corresponding application. In other words,information about a message/protocol/application corresponding to themessage of the broadcast property and information about amessage/protocol/application corresponding to the message of thenon-broadcast property may be provided. For example, the informationabout the application may include information such as a PSID. Themessage of the broadcast property and the message of the non-broadcastproperty may be designated using an ID per V2X application defined inIEEE 1609.12 etc. as the information about the application. Informationabout a receiver (e.g., a destination IP address) and information abouta transmitter (e.g. a source IP address) may be used as informationabout the messages of the broadcast/non-broadcast property.

Alternatively, an information message corresponding to V2V/V2I/V2P maybe designated as the broadcast property.

Alternatively, an information message corresponding to V2N may bedesignated as the non-broadcast property.

Alternatively, message properties may be distinguished according towhether a message is a V2X message related to safety or a V2X messagerelated to non-safety.

When a UE requests that a P-GW/L-GW transmit data to a specific APN/PDN,if the data does not use an IP address, the P-GW/L-GW may transmit thedata to a predesignated specific application server or a specific IPaddress.

Alternatively, when the UE requests that the P-GW/L-GW transmit data tothe specific APN/PDN, the P-GW/L-GW transmits the data to apredesignated specific application server or a specific IP addressregardless of information of a destination IP address of the data.

Alternatively, which IP should be used to transmit corresponding datawith respect to each V2X application or to which application server thedata should be transmitted may be designated to the P-GW/L-GW. Forexample, any P-GW or L-GW may be configured to use a source IP10.10.10.10 and a destination IP 10.10.10.11 for application 1 and asource IP 101.101.101.101 and a destination IP 101.101.101.111 forapplication 2. Next, upon receiving any data transmitted by the UE, theP-GW and/or L-GW analyzes the data. If the data is generated inapplication 1, the P-GW and/or L-GW may change or fill an IP headervalue using the source IP 10.10.10.10 and the destination IP 10.10.10.11and then transmit the data to an external network. If the data isgenerated in application 2, the P-GW and/or L-GW may change or fill theIP header value using the source IP 101.101.101.101 and the destinationIP 101.101.101.111 and then transmit the data to the external network.

The UE may determine whether a message to be transmitted thereby has thebroadcast property or the non-broadcast property according to theabove-described broadcast/non-broadcast information and transmitcorresponding data to an APN or PDN designated according to adetermination result.

FIG. 11 illustrates configuration of a UE and a network node accordingto a preferred embodiment of the present invention.

The UE 100 according to the present invention may include a transceiver110, a processor 120, and a memory 130. The transceiver 110 may bereferred to as a radio frequency (RF) unit. The transceiver 110 may beconfigured to transmit and receive various signals, data and informationto and from an external device. The UE 100 may be connected to thestorage device by wire and/or wirelessly. The processor 150 may controloverall operation of the UE 100, and be configured to calculate andprocess information for the UE 100 to transmit and receive to and fromthe external device. In addition, the processor 120 may be configured toperform the proposed operations of the UE. The memory 130 may store thecalculated and processed information for a predetermined time, and maybe replaced by another constituent such as a buffer (not shown).

Referring to FIG. 11, the network node 200 according to the presentinvention may include a transceiver 210, a processor 220 and a memory230. The transceiver 210 may be referred to as an RF unit. Thetransceiver 210 may be configured to transmit and receive varioussignals, data and information to and from an external device. Thenetwork node 200 may be connected to the storage device by wire and/orwirelessly. The processor 220 may control overall operation of thenetwork node 200, and be configured to calculate and process informationfor the network node 200 to transmit and receive to and from theexternal device. In addition, the processor 220 may be configured toperform the proposed operations of the network node. The memory 230 maystore the calculated and processed information for a predetermined time,and may be replaced by another constituent such as a buffer (not shown).

For configuration of the UE 100 and the network apparatus, the detailsdescribed in various embodiments of the present invention may beindependently applied or implemented such that two or more embodimentsare simultaneously applied. For simplicity, redundant description isomitted.

The embodiments of the present invention may be implemented throughvarious means. For example, the embodiments may be implemented byhardware, firmware, software, or a combination thereof.

When implemented by hardware, a method according to embodiments of thepresent invention may be embodied as one or more application specificintegrated circuits (ASICs), one or more digital signal processors(DSPs), one or more digital signal processing devices (DSPDs), one ormore programmable logic devices (PLDs), one or more field programmablegate arrays (FPGAs), a processor, a controller, a microcontroller, amicroprocessor, etc.

When implemented by firmware or software, a method according toembodiments of the present invention may be embodied as an apparatus, aprocedure, or a function that performs the functions or operationsdescribed above. Software code may be stored in a memory unit andexecuted by a processor. The memory unit is located at the interior orexterior of the processor and may transmit and receive data to and fromthe processor via various known means.

As described above, the detailed description of the preferredembodiments of the present invention has been given to enable thoseskilled in the art to implement and practice the invention. Although theinvention has been described with reference to exemplary embodiments,those skilled in the art will appreciate that various modifications andvariations can be made in the present invention without departing fromthe spirit or scope of the invention described in the appended claims.Accordingly, the invention should not be limited to the specificembodiments described herein, but should be accorded the broadest scopeconsistent with the principles and novel features disclosed herein.

The communication method described above is applicable to variouswireless communication systems including IEEE 802.16x and 802.11xsystems as well as a 3GPP system. Furthermore, the proposed method isapplicable to a millimeter wave (mm Wave) communication system using anultrahigh frequency band.

What is claimed is:
 1. A method of transmitting Internet protocol (IP)address information by a network node in a wireless communicationsystem, the method comprising: receiving an IP address allocationrequest from a user equipment (UE); allocating a specific IP addressdefined for vehicle-to-everything (V2X) communication to the UE when theIP address allocation request is for V2X communication; and notifyingthe UE of the specific IP address, wherein the same IP address as thespecific IP address is allocated to every UE requesting IP addressallocation for V2X communication.
 2. The method according to claim 1,wherein the IP address allocation request is received using a packetdata network (PDN) connectivity request message.
 3. The method accordingto claim 1, wherein the same IP address as the specific IP address isallocated to UEs requesting connectivity to a PDN for V2X communicationor transmitting an IP address allocation request associated with anaccess point name (APN) for V2X communication.
 4. The method accordingto claim 1, further comprising: receiving uplink V2X data using thespecific IP address.
 5. The method according to claim 4, furthercomprising: transmitting the uplink V2X data to an application serverfor V2X communication.
 6. The method according to claim 1, wherein thenetwork node is a packet data network gateway.
 7. A network node fortransmitting Internet protocol (IP) address information in a wirelesscommunication system, the network node comprising: a radio frequency(RF) unit; and a processor configured to control the RF unit, whereinthe processor controls the RF unit to receive an IP address allocationrequest from a user equipment (UE), allocate a specific IP addressdefined for vehicle-to-everything (V2X) communication to the UE when theIP address allocation request is for V2X communication, and notify theUE of the specific IP address, and wherein the same IP address as thespecific IP address is allocated to every UE requesting IP addressallocation for V2X communication.
 8. The network node according to claim7, wherein the IP address allocation request is received using a packetdata network (PDN) connectivity request message.
 9. The network nodeaccording to claim 7, wherein the processor identically allocates thespecific IP address to UEs requesting connectivity to a PDN for V2Xcommunication or transmitting an IP address allocation requestassociated with an access point name (APN) for V2X communication. 10.The network node according to claim 7, wherein the processor controlsthe RF unit to receive uplink V2X data using the specific IP address.11. The network node according to claim 10, wherein the processortransmits the uplink V2X data to an application server for V2Xcommunication.
 12. The network node according to claim 12, wherein thenetwork node is a packet data network gateway.
 13. A method of receivingInternet protocol (IP) address information by a user equipment in awireless communication system, the method comprising: transmitting an IPaddress allocation request to a network node; and receiving IP addressinformation about an IP address allocated to the UE from the networknode, wherein, if the IP address allocation request is forvehicle-to-everything (V2X) communication, a specific IP address definedfor V2X communication is allocated to the UE, and wherein the specificIP address is the same as that allocated to every UE requesting IPaddress allocation for V2X communication.
 14. The method according toclaim 13, wherein the IP address allocation request is transmitted usinga packet data network (PDN) connectivity request message.
 15. The methodaccording to claim 13, wherein the specific IP address is the same asthat allocated to UEs requesting connectivity to a PDN for V2Xcommunication or transmitting an IP address allocation requestassociated with an access point name (APN) for V2X communication. 16.The method according to claim 13, further comprising: transmittinguplink V2X data using the specific IP address.
 17. A user equipment (UE)for receiving Internet protocol (IP) address information in a wirelesscommunication system, the UE comprising: a radio frequency (RF) unit;and a processor configured to control the RF unit, wherein the processorcontrols the RF unit to transmit an IP address allocation request to anetwork node, and receive IP address information about an IP addressallocated to the UE from the network node, wherein if the IP addressallocation request is for vehicle-to-everything (V2X) communication, aspecific IP address defined for V2X communication is allocated to theUE, and wherein the specific IP address is identically applied to allUEs requesting IP address allocation for V2X communication.
 18. The UEaccording to claim 17, wherein the IP address allocation request istransmitted using a packet data network (PDN) connectivity requestmessage.
 19. The UE according to claim 17, wherein the specific IPaddress is the same as that allocated to UEs requesting connectivity toa PDN for V2X communication or transmitting an IP address allocationrequest associated with an access point name (APN) for V2Xcommunication.
 20. The UE according to claim 17, wherein the processorcontrols the RF unit to transmit uplink V2X data using the specific IPaddress.